On my 4.6 swap I used the cable and pedal from the Crown Vic swap and went thru the original hole on the fire wall of the Galaxie. So I had to remove the old pedal. I like the modern look of the new pedal better. The Crown Vic pedal bracket had to be modified slightly to work. The bracket needed to be extended slightly in order to push it away from the firewall as I wanted both brake pedal and gas pedal to be aligned. This made the gas pedal sit at an awkward angle so also had to adjust its position. So, a little cutting and welding of the gas pedal arm was in order.

I too am using a modern gas pedal.  Works well and looks good.